Leather working machine



NW. 25, 1969 J. E. BECKER 3,479,847

LEATHER WORKING MACHINE Filed Jan. 11, 1968 3 Sheets-Sheet 1 )a' INVENTOR. I JOHN E. BECKER BY M 5f? PATENT AGENTS Nov. 25, 1969 J. E. BECKER 3,479,847

LEATHER WORKING MACHINE Filed Jan. 11, 1968 3 Sheets-Sheet 2 F! G. 2 a

INVENTOR. JOH N E. BECKER Eli-i fl g f PATENT AGENTS NQV. 25, 31%69 J. E. BECKER 3,479,843

LEATHER WORKING MACHINE Filed Jan. 11, 1968 3 Sheets-Sheet 5 INVENTOR. JOHN E. BECKER PATE NT AGE NTS nite States Patent 3,479,847 LEATHER WORKING MACHINE John E. Becker, Bowmanville, Ontario, Canada, assignor to Robson Leather Company, Limited, Oshawa, Ontario, Canada Filed Jan. 11, 1968, Ser. No. 697,050 Int. Cl. C14b 1/34 US. CI. 69-46 14 Claims ABSTRACT OF THE DISCLOSURE The machine has two working stations through which the leather bends are passed successively by feed rolls; at each station the bend is engaged from beneath by an upwardly-urged flat bed, and from above by the lower run of an endless loop of rotatable leather-working rollers, the leather being squeezed and smoothed thereby. The two loops run in opposite directions transversely of the direction of movement of the bend through the machine, resulting in a machine that is balanced both statically and dynamically. Each loop squeezes the respective portion of the bend from the centre outward to the edge, the two loops overlapping so that the whole surface is worked. The means urging the bed upward comprise a pneumatic/hydraulic lever combination that adjusts automatically for the bend thickness and irregularities.

FIELD OF THE INVENTION This invention is concerned with improvements in or relating to leather working machines.

DESCRIPTION OF THE PRIOR ART In one form of leather working machine known hitherto, a ball or roller (known in the industry as a ball whatever its actual shape) is suspended in pendulum fashion above an operating bed and is moved back and forth by a suitable motor-driven reciprocating mechanism. A bend of leather to be worked and smoothed is laid upon the bed, which is then manually elevated by the operator, usually by means of a foot pedal and intervening mechanical linkage, to engage the ball with the bend. In addition to requiring a relatively large space to accommodate the bulky reciprocating mechanism, such machines are relatively low in throughput, and are noisy and tiring to operate, because of the physical effort required and the presence of considerable unbalanced vibration.

SUMMARY OF THE INVENTION It is another specific object to provide a new machine I having a new means for upward urging of the bed, so that the bed can adjust automatically for differences and irregularities in bend thickness.

In accordance with the present invention there is provided a leather working machine comprising a machine frame constituted by a plurality of spaced parallel platelike members, means mounted by the frame for feeding a bend of leather therethrough transverse to the plate-like members, means mounting between two immediately adjacent plate-like members a first plurality of leather working rollers for movement in a closed path parallel to the respective members and of generally oval shape with elongated upper and lower runs, means mounting between m ICC the last-mentioned plate-like members a cooperating first bed for supporting a bend of leather in engagement with the respective run of rollers, means mounting between another two immediately adjacent plate-like members a second similar plurality of said rollers and a respective similar cooperating second bed, the respective closed paths in which the rollers move overlapping upon a bend moved through the machine, and the directions of movement of the rollers of the two runs in contact with the bend being opposite to one another, means mounted by the frame for urging the beds toward their respective runs of rollers, means mounted by the frame for supporting the rollers to oppose the urging forces applied to the beds, and to support the rollers against the outwardlydirected centrifugal forces to which they are subjected at the ends of their respective paths.

Also in accordance with the present invention there is provided a leather working machine comprising a machine frame, means mounted by the frame for feeding a bend of leather therethrough, means mounting in the frame two separate pluralities of leather working rollers, each plurality being mounted for movement in a closed path of generally oval shape with elongated upper and lower runs, the respective closed paths overlapping upon a bend moved through the machine and the directions of movement of the rollers of the two runs in contact with the bend being opposite to one another, means mounting in the frame at least one bed member cooperating with the lower runs of the rollers to engage a bend with the rollers, and means mounted by the frame urging the bed for vertical movement toward the said lower runs of the rollers, the said bed urging means comprising at least one piston and cylinder unit operatively engaged between the frame means and the bed member and operative to urge the bed member toward the roller path upon the supply thereto of operating liquid under pressure, and means for supplying liquid operating fluid under pressure to the interior of the said unit, the said piston and cylinder unit having therein in addition a predetermined quantity of a gaseous operating fluid.

DESCRIPTION OF THE DRAWINGS A particular preferred embodiment of the invention is illustrated, by way of example, in the accompanying diagrammatic drawings, wherein:

FIGURE 1 is a perspective view from above and to one side of the whole machine, parts thereof being shown broken away as necessary for clarity of illustration,

FIGURE 2 is a plane partial cross-section, taken on the line 22 of FIGURE 1,

FIGURE 3 is a plane schematic partial cross-section, taken on the line 33 of FIGURE 2, and

FIGURE 4 is a partial schematic and partial crosssection to illustrate a particular detail of the operation of a bed elevating means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A frame for the machine is constituted by four relatively massive fiat metal plates 10 to 13 which are held in spaced-apart, parallel relation to one another by intervening tubular spacer members 14, the plates and the spacer members being connected and held rigidly together by through bolts 15. A pair of horizontal side bars 16 are fastened to the respective sides of the plates by means of suitable brackets and extend beyond the endmost plates 10 and 13. A horizontal entry table 17 is mounted by the bars 16 at the right hand end of the machine (as seen in FIGURE 1) while an exit table 18 is similarly mounted at the other end. The machine comprises three spaced pairs of feed rollers, namely an entry pair 19 rotatably mounted by brackets 20 between the entry table 17 and the plate an intermediate pair 21 rotatably mounted between the two inner plates 11 and 12 by brackets 22; and an exit pair 23 rotatably mounted by brackets between the exit table 19 and the plate 13. The lower roller of each pair is fixed in position, while the upper roller is spring urged toward the lower roller by springs accommodated in housings 24. All of these feed rollers are driven simultaneously, and at a speed that increases progressively by small amounts from the entry pair and through the intermediate pair to the exit pair, by a driving mechanism comprising a motor 25, a belt 26, pulley 27, sprocket 28, chain 29, larger sprocket 30, drive sprocket 31 and connecting chains 32. Guide plates 33 are provided above the path of the bends through the machine to ensure that the leading edges thereof cannot curl upwards and foul and jam the machine. Wire guards such as 34, of conventional form, are provided at the feed and exit ends of the machine, between the respective end plates and the tables, to enclose the feed rollers and thereby protect the operators.

A first leather working station is provided between the two plates 10 and 11, while a second essentially similar station is provided between the two plates 12 and 13. Each station comprises a plurality of heavy cylindrical rollers 35 (known in the trade as balls) of accurately formed cross-section, each being fast with a respective shaft 36. The rollers are connected together, equallv spaced from one another, to form a closed or endless loop, by means of an articulated linkage comprising two endless chains 37 on either side thereof, the chains being in driving mounting engagement with respective pairs of spaced sprockets 38. Each two immediately adjacent sprockets 38 are fast with a rotatably mounted shaft 39, one of each associated pair of shafts 39 protruding through the corresponding inner plate 11 or 12 and carrying a sprocket (not shown) drivably engaged with a chain 40, that in turn is drivably engaged by a sprocket 41 mounted on a shaft 42. The shaft 42 carries a pulley wheel 43 connected by a belt 44 to the pulley of a driving motor 45, each motor being movably mounted on the frame by any suitable means (not illustrated) to permit adjustment of the drive train.

In its passage through each station a bend moves over an upwardly urged bed 46 mounted on the upper surface of a respective I beam section 47, each section being guided in the frame for rectilinear up and down movement by two spaced pins 48 which pass through vertically elongated slots 49 in the beam. Each beam is mounted and urged for upward movement by a spaced pair of arm means 50, each pivotally mounted at one end by a shaft 51 between the respective frame plates. Two spaced bearing saddle members 52 fastened to the underside of the beam 47 are mounted on respective bearing shafts 53 of the respective arm means, while the other end of each arm means is pivotally connected by a rod 54 to a respective piston and cylinder unit 55. The lower end of each unit 55 is pivotally connected by a rod 56 to the frame means, and an upwardly urging force provided by the unit 55 produces a corresponding multiplied upward urging force pressing a bend carried by the bed 46 with predetermined pressure into engagement with the lower run of the respective plurality of rollers 35.

Referring especially now to FIGURE 3, it will be seen that the two closed paths followed by the respective pluralities of balls are of generally oval shape, each with its major axis parallel to the bed 46, and with flat elongated upper and lower runs, the two paths overlapping as viewed from the ends of the machine, so that the whole surface of the bend must be engaged and worked by the rollers. Moreover, the directions of movement of the two sets of rollers (indicated in the figure by arrows 57) are opposite to one another, so that each set will engage a bend fed centrally into the machine along the general longitudinal centre line thereof, and will smooth and roll it from the said centre line to the corresponding side edge, as is desired in the art. It may be noted that by use of two oppositely moving sets of rollers the resulting machine can be readily made both statically and dynamically balanced; as a practical result it is found that the machine as illustrated can be operated at full speed with little or no need to be secured to the floor on which it is mounted.

It will be noted that the pins 58 of the chains 37 extend inwards to engage between the teeth of the sprockets 38, and at spaced intervals the two parallel chains have an elongated pin 59 in common, whereby at all times each pair of sprockets 38 has a number of these pins 59 and the shafts 36 in engagement therewith so that the rolling axis of the rollers of each set will always be maintained accurately parallel to one another and to the general direction of movement of the bends. Each shaft 36 carries on both sides of the respective roller 35 a pair of rollers 60. These rollers 60 are engageable in their travel over the upper part of the path with the upper edges of a pair of parallel plates 61, which are supported between the respective frame plates by members 62, thereby preventing downward sagging of the upper run of the loop under the weight of the heavy rollers. In their travel over the lower part of the loop the rollers engage the lower edges of the plates 61 as the upwardly urged bed presses the bend and the rollers upward. Similarly, at the ends of the loop the rollers 60 engage the inner circular edges of end plates 63, mounted by members 64, thereby preventing the chains from disengagement with the sprockets under the very substantial cen trifugal forces of the heavy moving rollers. The ends of each shaft 36 are provided with respective further rollers 65 that are engageable with tracks 66 at the lower runs of the rollers to prevent, in the absence of a bend, the engagement of the highly finished rollers with the correspondingly highly finished bed, since such engagement will mar the said finishes and consequently mar the surface finish produced by the machine.

The direction of movement of a bend through the machine is from right to left in FIGURE 2, and it will be seen that the front or leading edges of the rollers are smoothly contoured so that the associated guide plates 33 can direct the leading edge of the bend under the rollers without fouling. The rear or trailing edges are of reduced diameter to provide a step into which the front edge of the associated guide plate protrudes, thereby preventing fouling caused by the tendency of the bend leading edge to curl upwards as it exits from the work station.

Referring now especially to FIGURE 4, each piston and cylinder unit 55 comprises an upstanding tubular member 67, a downward extending tubular member 68 which fits over the member 67 and suitable sealing means therebetween. A disc 69 is positioned in the member 67 on a shoulder 70 the space between the disc and the adjacent inner wall being sealed by an O-ring 71. Fluid under pressure (usually oil) is supplied to the interior of the unit via a connector 72, a pipe 73 and a pressure control valve 74, the oil being supplied under pressure from a reservoir 75 via a motor driven pump 76. It is an important feature of the present invention that an airfilled space 77 of predetermined volume is left above the oil level 78 in the unit. It is found that by suitable choice of the volume of air the resultant cushion or spring is just sufficient to accommodate automatically the differences in thickness of different bends encountered in normal operation, and also to accommodate automatically for variations in the thickness of a particular bend as it passes through the machine. A completely oil-filled unit is not as satisfactory, since the liquid is virtually incompressible and this automatic accommodation is not obtained.

In the operation of the machine the operator actuates the valve 74 to set the oil pressure to the value he knows from experience is required for a bend of the particular thickness to be worked. The bend is then fed into the machine and, as it passes through the first station, ap proximately one half thereof is rolled by the engagement of the highly-finished heavy rollers with the top surface of the bend, the above-described air spring ensuring that a completely smooth finish is obtained by the action of the rollers against the bend. The bend then passes through the second station, which then rolls the other half thereof so that a fully rolled bend is fed out onto the outlet table 19.

The longitudinal spacing of the two working stations of course ensures that a proper overlap of the working action is obtained, and an unrolled centre line is not left down the centre of the bend.

It will be understood by those skilled in the particular art that a particular embodiment has been described and illustrated and many modifications are possible within the scope of the appended claims. For example, in this embodiment the bed is movable and urged into contact with the rollers, but it is possible to employ a fixed bed with the rollers mounted and arranged to be urged toward the bed by means in addition to their own weight.

What I claim is:

1. A leather working machine comprising a machine frame constituted by a plurality of spaced parallel platelike members, means mounted by the frame for feeding a bend of leather therethrough transverse to the platelike members, means mounting between two immediately adjacent plate-like members a first plurality of leather working rollers for movement in a closed path parallel to the respective members and of generally oval shape with elongated upper and lower runs, means mounting between the last-mentioned plate-like members a cooperating first bed for supporting a bend of leather in engagement with the respective run of rollers, means mounting between another two immediately adjacent plate-like members a second similar plurality of said rollers and a respective similar cooperating second bed, the respective closed paths in which the rollers move overlapping upon a bend moved through the machine, and the directions of movement of the rollers of the two runs in contact with the bend being opposite to one another, means mounted by the frame for urging the beds toward their respective runs of rollers, means mounted by the frame for supporting the rollers to oppose the urging forces applied to the beds, and to support the rollers against the outwardly-directed centrifugal forces to which they are subjected at the ends of their respective paths.

2. A machine as claimed in claim 1, and comprising guide means mounted by the frame for guiding the leading edge of a bend emerging from a preceding feeding means between the succeeding rollers and their cooperating bed, and for guiding the leading edge of a bend emerging from between the last-mentioned rollers and bed to a succeeding feeding means, wherein the trailing edge of each roller is recessed and the respective guide means for guiding a bend that has passed between the roller and its bed has its leading edge extending into the said recess.

3. A machine as claimed in claim 1, wherein each roller has associated therewith support means cooperating with the frame to prevent sagging of the rollers under their weight in the upper runs of their paths.

4. A machine as claimed in claim 1, wherein each roller has associated therewith support means cooperating with the frame to support the rollers against engagement with the cooperating bed in the absence of a bend between them.

5. A machine as claimed in claim 4, wherein the said support means comprise a pair of spaced roller means for each roller coaxially mounted with its roller and rotatable about its axis of rotation, the roller means being disposed on either side thereof and engageable with corresponding support surfaces mounted by the machine frame.

6. A machine as claimed in claim 1, wherein the said frame comprises four spaced plate-like members, a pair of entry feed rolls is mounted adjacent one outermost member at the entrance to the machine; a pair of exist feed rolls are mounted adjacent the other outermost member at the exit from the machine, one plurality of rollers is mounted between one outermost member and its immediately adjacent inner member, the other plurality of rollers is mounted between the other outermost member and its immediately adjacent inner member, and a pair of intermediate feed rolls is mounted between the said two inner frame members.

7. A machine as claimed in claim 1, wherein each said bed comprises a bed member mounted by the frame for vertical movement toward and away from the cooperating rollers, at least one piston and cylinder unit operatively engaged between the frame means and the bed member and operative to urge the bed member toward the roller path upon the supply thereto of operating liquid under pressure, and means for supplying liquid operating fluid under pressure to the interior of the said unit, the said piston and cylinder unit having therein in addition a predetermined quantity of a gaseous operating fluid.

8. A machine as claimed in claim 7, wherein respective lever arm means are interposed between each bed member and the respective piston and cylinder unit, the said bed member comprises a relatively rigid member extending beneath the lower run of the respective roller path, at least two saddle bearing members mounted on the underside of the rigid member, spaced longitudinally thereof and resting upon corresponding bearing members of the said lever arm means disposed intermediate the length of the arm means to provide a division of the mechanical movement and multiplication of the urging force provided by the piston and cylinder unit 9. A leather working machine comprising a machine frame, means mounted by the frame for feeding a bend of leather therethrough, means mounting in the frame two separate pluralities of leather working rollers, each plurality being mounted for movement in a closed path of generally oval shape with elongated upper and lower runs, the respective closed paths overlapping upon a bend moved through the machine and the directions of movement of the rollers of the two runs in contact with the bend being opposite to one another, means mounting in the frame at least one bed member cooperating with the lower runs of the rollers to engage a bend with the rollers, and means mounted by the frame urging the bed for vertical movement toward the said lower runs of the rollers, the said bed urging means comprising at least one piston and cylinder unit operatively engaged between the frame means and the bed member and operative to urge the bed member toward the roller path upon the supply thereto of operating liquid under pressure, and means for supplying liquid operating fluid under pressure to the interior of the said unit, the said piston and cylinder unit having therein in addition a predetermined quantity of a gaseous operating fluid. I 10. A machine as claimed in claim 9, and comprising guide means mounted by the frame for guiding the lead ing edge of a bend emerging from a preceding feeding means between the succeeding rollers and their cooperating bed, and for guiding the leading edge of a bend emerging from between the last-mentioned rollers and bed to a succeeding feeding means, wherein the trailing edge of each roller is recessed and the respective guide means for guiding a bend that has passed between the roller and its bed has its leading edge extending into the said recess.

11. A machine as claimed in claim 9, wherein each roller has associated therewith support means cooperating with the frame to prevent sagging of the rollers under their weight in the upper runs of their paths.

12. A machine as claimed in claim 9, wherein each roller has associated therewith support means cooperating with the frame to support the rollers against engagement with the cooperating bed in the absence of a bend between them.

13. A machine as claimed in claim 12, wherein the said support means comprise a pair of spaced roller means for each roller coaxially mounted with its roller and rotatable about its axis of rotation, the roller means being disposed on either side thereof and engageable with corresponding support surfaces mounted by the machine frame.

14. A machine as claimed in claim 9, wherein respective lever arm means are interposed between each bed member and the respective piston and cylinder unit, the said bed member comprises a relatively rigid member extending beneath the lower run of the respective roller path, at least two saddle bearing members mounted on the underside of the rigid member, spaced longitudinally thereof and resting upon corresponding bearing members of the said lever arm means disposed intermediate the length of the arm means to provide a division of the mechanical movement and multiplication of the urging force provided by the piston and cylinder unit.

References Cited UNITED STATES PATENTS 903,181 11/1908 Dodge 6946 978,120 12/1910 Engelman 6946 1,450,933 4/1923 Wilks 6946 1,920,341 8/1933 Ballard 69-46 2,366,242 1/1945 Edgar 69-46 2,396,421 3/1946 Henning 69-46 2,540,132 2/1951 McMath et al 6946 2,679,827 6/1954 Perdue 92134 X 2,721,469 10/1955 Metzger 69- 46 ALFRED R. GUEST, Primary Examiner 

